The Effects of Environmental Toxicology on Daphnia

Background information Daphnia Magna is an arthropod that can grow up to 5 mm. It is a filter feeder meaning it feeds off of suspended particles in the water. Daphnia can consume particles that range from 1µ to 50µ. The heart of Daphnia is located dorsally meaning it's located in the back. The heart rate of Daphnia can range due to many variables, one being temperature. "At a temperature averaging 20o C its heart rate is about 200 beats per minute."2 As the temperature surrounding the Daphnia decreases so does its heart rate. Daphnia has a transparent body which allows one to see its organs. This is why Daphnia is often used in experiments dealing with heart rate. Daphnia inhibits regions of fresh water. They will not survive very long in distilled water or tap water. The reason why they would not survive long in tap water is the amount of chlorine. The amount of chlorine is so high that it would eventually kill the Daphnia. If tap water were ever to be used to host a Daphnia it would have to sit for a period of at least 24 hours in order for the chlorine amount to decrease and therefore become habitable for the Daphnia.

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For many years people have used salt during blizzards to uncover rode's for safer driving. What some may not know is the impact road salt can have on the environment and the organisms that live in it. "Road salts can have affects on organisms who inhibit wetlands as far as 550 feet from the roads. "4This is due to the many chemicals as well as dye that road salt contain. Both of these factors impact living things that range from trees to amphibians. When the road salt reaches high enough concentration it becomes highly acidic. As the road salt reaches the grass and soil, the salt is absorbed by the soil and affects many organisms. "In contrast to their tolerance of low oxygen, Daphnia are very sensitive to disturbances of the ionic composition of their environment."5 When Daphnia are exposed to salt after a certain period